Calling Fiesta one of the most joyous times of the year, Mayor Julián Castro added his voice Wednesday to the chorus of officials who have assured the public that security would be tight and the event safe.

The decision to address security — something that usually is not done prior to Fiesta's opening — was made in the wake of the Boston Marathon bombings Monday that killed three people and left more than 170 people wounded.

Flanked by the police and fire chiefs plus City Manager Sheryl Sculley, Fiesta organizers and City Council members, Castro said no one should avoid the city's largest party because of nervousness over safety.

“This has reminded us that every single community must be vigilant for the possibility of something similar,” Castro said. “We encourage folks to attend with their families and have a good time. Fiesta is safe and it always been. This year is no different.”

About 3.6 million people are expected to attend Fiesta events during the 10-day stretch and the parades usually attract an average of 350,000 people, officials said.

Fiesta Commission CEO John Melleky and President Marilyn Eldridge said they haven't heard concerns directly from volunteers or the more than 100 nonprofit organizations that participate.

But with Boston on everyone's mind, they know there could be anxiety.

“This is a very family-friendly festival,” Melleky said. “There's something for kids or for seniors, and that's how it's always been.”

Officials said suspicious activity can be reported by calling 210-225-8477 or sending a text to 847411. Emergencies should still be reported to 911.